The present invention concerns a screw cap for closure of a container, said screw cap having a screw cap body and a safety seal device with a continuous band section and a tear-off strip joined to it, said band section having internal blocking elements on its inside, each with a leading slope and a locking surface, said container having outer locking elements that mesh with the inner locking elements when the container is closed and are arranged along its outer periphery at its opening, said band section also being joined to the screw cap body via first breakaway webs.
First closure of such a container to achieve locking of the locking elements occurs by a screw motion between the screw cap and container. On achieving thread engagement the tooth-like locking elements of the screw cap and of the container begin to slide one over the other, during which the locking elements slide or snap into the locking position over their leading slopes and movement in the opening direction is prevented by mutual contact of the locking surfaces of the locking elements.
The locking elements of the screw cap are arranged on a safety seal, which is torn off the screw cap body to open the container. For this purpose the safety seal is joined to the body of the screw cap via webs, said webs being broken during tearing of the safety seal from the screw cap by the force effect of the user.
When the locking elements slide over each over for locking during the rotary movement, yielding movements of these locking elements necessarily occur. Whereas elastic deformations occur in the locking elements of the mentioned type, especially in the case of plastic, permanent plastic deformations can also occur. Contrarily, if a relatively soft, i.e., elastic material is used, there is a hazard that locking between the locking elements is not secure because the locking elements can also yield elastically during unpermitted twisting movement and thus release the screw cap.
Containers, especially compressible containers and tubes that are intended to release, for example, eyedrops or nosedrops, have an elongated spout, a nozzle. When such containers are produced by means of an injection molding process, the spout is first closed at its tip and, in order to release the discharge opening at the tip, the tip of the spout is cut off with a knife. A sharp edge that can lead to injury is thus produced at the discharge opening of the spout. This edge has thus far been rounded off, among other things, by the action of heat, during which there is a hazard that the passage in the discharge opening is narrowed too much or even melted together.